1. Field of the Invention
This invention relates to a webbing retractor equipped with an emergency locking mechanism and suitable for use in an aircraft, car or the like, and more specifically to an emergency locking retractor permitting easy release of a webbing from its lockup state.
2. Description of the Prior Art
Known emergency locking retractors may generally be classified into two types, one being the vehicle sensing type in which a webbing is locked by sensing an acceleration of a vehicle body in the event of an emergency and the other being the webbing sensing type in which the locking of a webbing is effected by sensing an abrupt release of the webbing in the event of an emergency. Of these two types of emergency locking retractors, webbing-sensing emergency locking retractors are in many instances of such a design that an inertia member is attached to a shaft, on which a webbing is taken up, rotatably relative to the shaft and by making use of a relative rotation developed between the shaft and inertia member upon an abrupt release of the webbing, a pawl is brought into engagement with a ratchet plate provided coaxially on the shaft so as to prevent any further rotation of the shaft. In such an emergency locking retractor, the webbing is promptly taken up by a take-up spring provided with the shaft and is received over the entire length thereof within the retractor upon release of the buckle by an occupant. Here, the rotation of the shaft is stopped suddenly while the inertia member tends to continue its rotation owing to its own inertia. A relative rotation is thus developed between the shaft and the inertia member, thereby bringing about such a state that the pawl is engageable with the ratchet plate. Since the shaft is caused to rotate slightly in the webbing-releasing direction owing to a counter-reaction to the sudden stop, the above-established state is enhanced further and in relatively many instances, the so-called lockup state permitting neither release nor take-up of the webbing is resulted. Such a lockup state also occurs in the case of an emergency locking retractor of the vehicle sensing type (for example, when its sensor is actuated by an impact upon taking up the webbing). In order to release the above lockup state, it is necessary to disassemble the retractor in the worst case. This is extremely inconvenient.